This invention relates to electrical terminal structures, and more specifically relates to a novel insulation board mounted terminal strap structure in which terminals are securely fastened to the insulation board.
The securement of thin, conductive terminal straps to a common insulation board is quite well known. For example, in many well-known relatively low power switches an electrical contact is fixed to one surface of an insulation board and has an elongated terminal extending through the board and outwardly from the board to serve as a solderable or plug-in terminal. The contact portion of the strap lies flat over the top surface of the insulation board and can make contact with a sliding contact mounted for movement in the same housing which receives the insulation board and its terminals. There are other well-known applications for electrical terminals which are secured to an insulation board.
It is necessary that these devices be inexpensive but that they have great reliability since a failure by loosening of a simple inexpensive terminal could disable an appliance or the like. Various methods have been used for securing the terminal to the insulation board. One known method which is relatively inexpensive is to bend the terminal to a U shape, and then insert the terminal strap through spaced slots in the board. A short leg of the U-shaped strap is then bent upwardly to wrap under the bottom of the board, with its end terminating at a point between two spaced slots. The end of the short leg may also be staked into the bottom of the board. This kind of structure frequently fails because, when relatively small forces are applied to the extending terminal end of the contact strap, the wrapped-around portion of the strap can open and less securely grip the board. On occasion relatively small forces can pull the strap completely off the board.